Can I sit a Bellingham ADU on the alley line?
✓ Verified against code · August 20, 2026
Yes. Bellingham requires 5 ft to the side and rear generally, but imposes no side or rear setback at all where the lot abuts a public alley. A detached ADU may also occupy the rear yard and the rear 22 ft of an interior side yard.
Citation: BMC 20.10.036
How current is this?
Bellingham’s ADU rules run under BMC 20.10.036 (Accessory Dwelling Units) (Ordinance 2025-12-035 §2). Bellingham completed its HB 1337 alignment in Ordinance 2025-12-035, effective December 23, 2025 — roughly six months after the state's June 30 deadline. Two of the standards below rest on interim ordinances rather than permanent code: the citywide elimination of parking minimums, and the companion infill regulations that sunset in December 2026. We verified this answer against primary sources on August 20, 2026, and every change we catch is logged in the changelog.
More Bellingham ADU questions
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Not legal advice — lot-specific overlays can change the answer for your parcel. The citation above points at the governing code section; check it, or ask the city to confirm.